4P + 5O2 =点燃= 2P2O5
124g 160g
12.4g m=160g×12.4g÷124g=16g
n(O2)=m/M=16g÷32g/mol=0.5mol
也可直接计算 4P + 5O2 =点燃= 2P2O5
124g 5mol
12.4g n=5mol×12.4g÷124g=0.5mol
完全燃烧12.4g红磷,需要消耗氧气物质的量
4P + 5O2 =点燃= 2P2O5
124g 160g
12.4g m=160g×12.4g÷124g=16g
n(O2)=m/M=16g÷32g/mol=0.5mol
也可直接计算 4P + 5O2 =点燃= 2P2O5
124g 5mol
12.4g n=5mol×12.4g÷124g=0.5mol